1. Field of the Invention
The present invention relates to devices for applying a particular level of torque to an orthopedic implant component and, more particularly, to a torque limiting driver for applying a particular level of torque to an orthopedic implant component that can be easily disassembled for sterilization of the torque limiting driver components.
2. Background Information
Various types of orthopedic implants such as spine implants and joint prosthetics typically utilize and/or rely on components that must be securely attached to other components of the implant or to various parts of the body. The integrity and/or effectiveness of the implant may depend upon proper attachment of the component. Particularly, if the component is either over-tightened or under-tightened, there can be associated negative effects. For example, an under-tightened component may loosen causing the loss of effectiveness of a component, while an over-tightened component may impart an undesirable amount of stress on one or more components.
Implants are thus attached using devices that will allow the surgeon to apply the necessary torque throughout the attachment process, since a certain level of torque is required to properly secure a component. It is often difficult, however, to ascertain when the proper level of torque has been imparted on an implant component and, in turn, when the implant component has been securely attached.
In order to alleviate these problems, torque-limiting devices or drivers have been developed to help ensure that a consistent or limited assembly torque is imparted on implant components in order to properly secure torque-applied implant components to other implant components and/or body parts. Torque-limiting drivers are calibrated to impart a desired level of torque to an implant component during implant thereof. Other torque-limiting drivers offer user adjustable calibration for varying the level of applied torque. A problem with these prior art torque-limiting drivers is their complexity and/or their ability to be disassembled for cleaning. Another problem with these prior art torque-limiting drivers is there lack of being able to be medically sterilized.
Current federal regulations (e.g. FDA regulations) do not require medical instruments to be able to be disassembled. It is anticipated, however, that future federal regulations will require that some or all medical instruments be able to be disassembled, especially for complete sterilization of the instrument.
Because, as pointed out above, current torque-limiting drivers cannot be disassembled or they include parts that can be medically sterilized, there exists a need for a torque-limiting driver that can be disassembled for medical sterilization. There is also a need for a torque-limiting driver that can be easily reassembled after medical sterilization.